First of all thx for the great plugin. But I have the same or a similar problem as siricar.
If I edit/add credits for an image in the media library everything works fine, also if I add a new image to a post. But if I try to update or add credits to an existing image of an editors post it didn’t work. It appears a loading icon in the input field and if I hit the update/save button an error shown up in the console.
Console:
Uncaught TypeError: Cannot read property 'attr' of undefined
media-credit-tinymce.js?wp-mce-4310-20160418:796
WordPress Version: 4.52 + 4.53
Theme: customized/proprietary theme.
We are using multiple plugins, but the error seems not related to them. I disabled all but same problem.
